A gate thick film resistor and an IGBT power module

Abstract

This utility model relates to a gate thick-film resistor and an IGBT power module. The gate thick-film resistor includes a ceramic substrate, a positive electrode layer printed on the front side of the ceramic substrate, and a back electrode layer printed on the back side of the ceramic substrate. A resistive layer is printed on the positive electrode layer, a glass layer is printed on the resistive layer, and a protective layer is covered on the glass layer. All layers are sintered together in a sintering furnace at a high temperature of 600-1000°C. In the technical solution of this utility model, by increasing and optimizing the design, improving the process, selecting materials, and optimizing the process, the performance and stability of the gate resistor are improved, making it suitable for power semiconductor wire bonding processes and more applicable to IGBT power module applications.

Description

Technical Field

[0001] This utility model relates to the field of electronic components technology, and in particular to a gate thick film resistor, its preparation method, and an IGBT power module. Background Technology

[0002] IGBT (Insulated Gate Bipolar Transistor) power modules are a new generation of semiconductor devices and are very important for rail transit such as high-speed rail and EMU trains. IGBT modules have a series of advantages such as easy driving, simple switching control, fast switching rate, and low power loss, and are widely used in frequency converters and power system equipment.

[0003] Currently, both domestic and international manufacturers use IGBT modules as the core component of rail transit vehicles. However, my country relies on importing and reprocessing these inverters, which not only lengthens the construction cycle but also increases the cost of building rail transit networks. Therefore, the development of IGBT module technology in my country remains a critical bottleneck that urgently needs to be overcome, and it is essential for the construction of my country's rail transit network.

[0004] The performance of the gate resistor directly affects the overall performance of the IGBT power module. Besides limiting the gate's charging and discharging current and influencing the IGBT's switching speed, the gate resistor also reduces power losses in the drive circuit, reduces electromagnetic interference, prevents gate oscillation, and avoids parasitic turn-on. Currently, domestically produced IGBT power modules primarily use imported resistors. While thin-film resistors are commonly used in China, they present several problems under high power, high frequency, and high temperature environments, such as high power consumption, high temperature rise, and poor stability. Summary of the Invention

[0005] This utility model aims to solve at least one of the technical problems existing in the prior art or related technologies.

[0006] Therefore, one objective of this utility model is to provide a gate thick film resistor, its preparation method, and an IGBT power module. By increasing optimized design, improving processes, selecting materials, and optimizing processes, the performance and stability of the gate resistor are improved, making it more suitable for IGBT power module applications.

[0007] To achieve the above objectives, the first aspect of this utility model provides a gate thick film resistor for an IGBT power module, comprising a ceramic substrate, a positive electrode layer printed on the front side of the ceramic substrate, and a back electrode layer printed on the back side of the ceramic substrate. A resistive layer is printed on the positive electrode layer, a glass layer is printed on the resistive layer, and a protective layer is covered on the glass layer. The layers are sintered together at a high temperature of 600-1000°C in a sintering furnace.

[0008] In the above technical solution, preferably, the thickness of the resistive layer after sintering is 5-50 μm.

[0009] In the above technical solution, preferably, the ceramic substrate is an alumina ceramic substrate or an aluminum nitride ceramic substrate, with a thickness of 0.2-1.2 mm.

[0010] In the above technical solution, preferably, both the positive electrode layer and the back electrode layer include a first printing layer and a second printing layer, and the second printing layer is printed after the first printing layer is cured.

[0011] In the above technical solution, preferably, the thickness of the first printed layer after curing is 5-50 μm, and the total thickness of the first printed layer and the second printed layer after curing is 10-50 μm.

[0012] The second aspect of this utility model provides an IGBT power module, which includes a gate thick-film resistor provided by the first aspect of this utility model. The gate thick-film resistor is matched with the IGBT gate drive circuit in the IGBT power module.

[0013] Compared with existing technologies, the advantages of the gate thick-film resistor and IGBT power module provided by this invention are as follows: by increasing optimized design, improving processes, selecting materials, and optimizing processes, the performance and stability of the gate resistor are improved, making it more suitable for IGBT power module applications. The development and application of this technology will help improve the performance and reliability of IGBT power modules, can replace similar imported products, fill domestic technological gaps, and solve the problem of being "stuck" by foreign technology in this field. Attached Figure Description

[0014] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 A layer structure diagram of the gate thick film resistor involved in an embodiment of the present invention is shown; Figure 2 A flowchart illustrating the preparation method involved in an embodiment of this utility model is shown; in, Figures 1 to 2 The correspondence between the reference numerals and component names in the attached drawings is as follows: 1. Ceramic substrate; 2. Positive electrode layer; 3. Back electrode layer; 4. Resistive layer; 5. Glass layer; 6. Protective layer. Detailed Implementation

[0015] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0016] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0017] (1) IGBT (Insulated-Gate Bipolar Transistor) is an insulated-gate bipolar transistor.

[0018] It is a composite fully controllable voltage-driven power semiconductor device. Structurally, the IGBT combines the insulated gate structure of the MOSFET (metal-oxide-semiconductor field-effect transistor) with the bipolar conductivity of the bipolar junction transistor (BJT).

[0019] In terms of its working principle, the IGBT controls the current flow between the collector and emitter by applying a voltage between the gate and emitter. When the gate-emitter voltage exceeds the threshold, the IGBT turns on, allowing a large current to flow; when the gate-emitter voltage is below the threshold, the IGBT turns off, blocking the current.

[0020] IGBTs have a wide range of applications. In the field of power electronics, they are key components in motor drive systems, frequency converters, switching power supplies, and other equipment, used to efficiently control and convert electrical energy. For example, they play a crucial role in motor control of electric vehicles and motor speed regulation in industrial automation.

[0021] (2) IGBT gate thick film resistor is a thick film power resistor used in the gate circuit of IGBT (Insulated Gate Bipolar Transistor).

[0022] Structurally, it mainly consists of a ceramic substrate 1 and a thick-film resistive material. The thick-film resistive material is printed onto the ceramic substrate 1 using processes such as screen printing to form a resistor with a certain resistance value.

[0023] Functionally, it plays a crucial role. First, it limits the gate current of the IGBT, preventing excessive gate current from damaging the device. Second, it controls the switching speed of the IGBT; an appropriate resistance value helps optimize the IGBT's turn-on and turn-off processes, reducing switching losses and electromagnetic interference. For example, in high-frequency switching circuits, adjusting the resistance value of the gate thick-film resistor can make the IGBT's switching process smoother, thereby improving the overall circuit performance and reliability.

[0024] Introduction to gate thick-film resistors for IGBT power modules: Working principle In IGBT power modules, the gate thick-film resistor primarily controls the gate current. When a voltage is applied to the IGBT gate, the gate acts as a capacitor. The thick-film resistor and this gate capacitance form an RC circuit. By limiting the current, the charging and discharging speed of the capacitor is controlled, thus affecting the IGBT's switching speed, turn-on and turn-off times. Simultaneously, it also limits noise, parasitic inductance, and capacitance in the gate drive path, reducing electromagnetic interference and ringing effects.

[0025] Features and advantages High power handling capacity: Thick film technology allows resistors to withstand higher power, meeting the operating requirements of IGBT power modules under high voltage and high current conditions, and can handle high peak loads in a short time.

[0026] Stable resistance value: It can maintain a relatively stable resistance value under different working environments and conditions, and is less affected by factors such as temperature and voltage, thereby ensuring the gate control accuracy and stability of the IGBT power module.

[0027] Excellent surge protection: Compared with thin film resistors, they generally have better surge protection and overload capacity, and can withstand instantaneous high voltage and high current surges during the switching process of IGBT power modules without easily overheating or being damaged.

[0028] Reliable wire bonding capability: Utilizing a specially designed process, it is suitable for IGBT electrode wire bonding, including gold wire bonding, copper wire bonding, and aluminum wire bonding, ensuring reliable and stable bonding quality.

[0029] Application areas New energy vehicles: In key components of new energy vehicles, such as on-board charging circuits, battery management systems, DC / DC voltage conversion of batteries, and inverter circuits for motor drives, IGBT power module gate thick film resistors can ensure stable system operation.

[0030] Industrial Automation: In equipment such as frequency converters and servo drives in the field of industrial automation, IGBTs are used to control the switching of motors, thereby achieving speed regulation and control of motors and ensuring the efficient and stable operation of the equipment.

[0031] Power electronic equipment, such as switching power supplies and uninterruptible power supplies, helps improve power conversion efficiency and stability, reduce electromagnetic interference, and enhance equipment performance and reliability.

[0032] Development trend High performance: As IGBT power modules develop towards higher voltage, larger current and higher frequency, the performance requirements for gate thick film resistors will continue to increase, such as lower temperature coefficient, higher precision and smaller parasitic inductance.

[0033] Miniaturization and integration: To adapt to the trend of miniaturization of electronic devices, the gate thick film resistors of IGBT power modules will develop towards smaller size and higher integration, such as by adopting multilayer thick film technology and chip-level packaging, to achieve high integration with IGBT modules.

[0034] High reliability and stability: In some applications with extremely high reliability requirements, such as aerospace and military fields, the requirements for the reliability and stability of gate thick film resistors will be more stringent, and it is necessary to further improve their anti-aging, anti-radiation, and anti-vibration performance.

[0035] Domestic substitution is accelerating: The technology level of gate thick film resistors for domestic IGBT power modules is constantly improving, and domestic substitution is accelerating. Related domestic manufacturers are expected to occupy a larger market share in the future.

[0036] like Figure 1 As shown, a gate thick film resistor for an IGBT power module according to an embodiment of the present invention includes a ceramic substrate 1, a positive electrode layer 2 printed on the front side of the ceramic substrate 1, and a back electrode layer 3 printed on the back side of the ceramic substrate 1. A resistive layer 4 is printed on the positive electrode layer 2, a glass layer 5 is printed on the resistive layer 4, and a protective layer 6 is covered on the glass layer 5. The layers are sintered together at a high temperature of 600-1000°C in a sintering furnace.

[0037] Specifically, the width of the ceramic substrate 1 is greater than the width of the positive electrode layer 2, the back electrode layer 3, the resistive layer 4, the glass layer 5, and the protective layer 6. The width of the ceramic substrate 1 is greater than the width of the positive electrode layer 2 and the back electrode layer 3, which is more conducive to the complete adhesion of the positive and back electrode layers to the ceramic substrate. The width of the resistive layer 4 is smaller than that of the positive electrode layer 2, the glass layer 5, and the protective layer 6, respectively. The width of the resistive layer 4 is smaller than that of the positive electrode layer 2, which can ensure the overlap effect between the resistive layer 2 and the positive electrode layer 2 while retaining the welding position of the positive electrode layer 2. The width of the resistive layer 4 is smaller than that of the glass layer 5 to ensure that the glass layer can cover the entire resistive layer and ensure that the resistive layer is not damaged by the outside. The width of the glass layer 5 is smaller than that of the protective layer 6 to ensure that the protective layer can completely cover the entire glass layer and provide sufficient protection for the resistive layer 4, the glass layer 5, and the resistance adjustment notch.

[0038] In this embodiment, the gate thick-film resistor mainly consists of a ceramic substrate 1, electrode paste, resistor paste, and protective paste. The electrode paste is printed on the back side of the substrate, while the positive electrode paste, resistor, and protective layer 6 are printed on the front side of the ceramic substrate 1. The specific structure is as follows: Figure 1 As shown, the electrodes and resistive paste are printed on the ceramic substrate 1 and then sintered at high temperature to bond tightly with the ceramic substrate 1. The protective paste covers the resistive layer 4 and is fused with the resistive layer 4 after high temperature sintering to achieve a protective effect.

[0039] In the above technical solution, preferably, the ceramic substrate 1 is an alumina ceramic substrate 1 or an aluminum nitride ceramic substrate 1, with a thickness of 0.2-1.2 mm.

[0040] In the above technical solution, preferably, both the positive electrode layer 2 and the back electrode layer 3 include a first printing layer and a second printing layer, and the second printing layer is printed after the first printing layer is cured.

[0041] In the above embodiments, preferably, the thickness of the sintered resistive layer 4 is 5-50 μm.

[0042] In the above embodiments, preferably, the thickness of the cured first printed layer is 5-50 μm, and the total thickness of the first and second printed layers after curing is 10-50 μm. Since the printing paste undergoes drying testing after the first and second printing processes, the measured film thickness is the low-temperature drying thickness. After printing on both sides, it undergoes high-temperature sintering and curing, causing the paste to completely shrink and adhere to the ceramic substrate. Therefore, the sintered thickness may be lower than the dried thickness.

[0043] In this embodiment, film thickness detection: Contact-type film thickness gauges are generally suitable for measuring the overall thickness of materials. The testing principle of a mechanical contact thickness gauge is as follows: one side of a pre-treated thin sample is placed on the lower measuring surface, and the upper measuring surface, parallel to and centered with the lower measuring surface, is pressed onto the other side of the thin sample with a certain pressure. The sensor integrated with the measuring head automatically detects the distance between the upper and lower measuring surfaces, which is the thickness of the thin sample. Our printed electrodes, resistors, and glass layer 5 all have certain thickness requirements; the film thickness gauge can detect the thickness range of each printed layer.

[0044] like Figure 2 As shown, a method for fabricating a gate thick-film resistor for an IGBT power module according to another embodiment of the present invention includes the following steps: S1, using a first screen with 150-600 mesh, silver-palladium paste is printed on the front and back sides of ceramic substrate 1; S2, after being dried and cured in a drying oven at 100-450℃, is placed in a sintering furnace for pre-sintering at 600-1000℃; S3, after sintering, the silver-palladium paste is printed a second time using the first screen with a mesh of 150-600. S4, after being dried and cured in a drying oven at 100-450℃, is placed in a sintering furnace for co-sintering at 600-1000℃ to form the positive electrode layer 2 and the back electrode layer 3. In steps S1 to S4, the drying film thickness of the electrode is accurately calculated based on the required electrode sintering film thickness and the sintering shrinkage rate of the paste. The printing thickness is controlled by the calculated drying film thickness. The thickness should be moderate, meeting the usage requirements without being too thick, which would waste materials. For the printing screen, a high-strength stainless steel 150-600 mesh first screen is selected. Stainless steel screens have the characteristics of strong wear resistance, stability, and good paste throughput. The electrode paste uses silver-palladium paste, which has the characteristics of strong adhesion and excellent oxidation resistance.

[0045] S5, the paste is printed onto the positive electrode layer 2 using a second screen with a mesh size of 150-600; S6, after being dried and cured in a drying oven at 100-450℃, is placed in a sintering furnace for pre-sintering at 600-1000℃; S7. After sintering, the paste is printed a second time using a second screen with a mesh of 150-600 mesh. S8, after being dried and cured in a drying oven at 100-450℃, is placed in a sintering furnace for co-sintering at 600-1000℃ to form a resistance layer 4; In steps S5 to S8, resistor printing is a key control process in the processing of this product. It is necessary to control the thickness of the resistor printing and ensure the uniformity of the resistor film thickness. For resistor printing, a high-strength stainless steel 150-600 mesh second screen is used. The printing thickness is accurately calculated by verifying the sintering shrinkage rate of the resistor paste and the target film thickness to meet the printing requirements. After multiple verifications, the paste type is finally determined. Ruthenium-based resistor paste, such as RU type paste, is used. The sintering film thickness is controlled at 5-50μm. Finally, the resistor printing and curing conditions are determined.

[0046] S9, a glass paste is printed on the resistive layer 4, dried in a drying oven at 100-450°C, and then sintered in a tunnel sintering furnace at 500-800°C to form the glass layer 5. In this step, the tunnel sintering furnace typically uses far-infrared radiation to heat the interior, ensuring that infrared light reaches every corner of the furnace for uniform heating and energy transfer to the material. Different electrodes, resistors, and glass layer pastes are then screen-printed onto the substrate. These pastes are then sintered at high temperatures in the sintering furnace to form a stable functional coating. The tunnel sintering furnace has different temperature zones; by setting different temperature profiles for different paste requirements, the paste is fixed onto the ceramic substrate, achieving the requirements for thick-film resistors.

[0047] S10, after laser trimming, a second layer of glass paste is printed on the glass layer 5, dried in a drying oven at 100-450℃, and after inspection, it is placed in a tunnel sintering furnace at 500-800℃ for sintering to form a protective layer 6.

[0048] In this embodiment, the multi-layer structure of the gate thick film resistor, including the electrode layer, resistive layer 4, and protective layer 6, is printed onto the ceramic substrate 1 using a screen printing machine. The screen printing machine transmits power via a transmission mechanism, causing the squeegee to squeeze the ink and screen printing plate during movement, forming an imprint line between the screen printing plate and the substrate. Due to the tensions N1 and N2 of the screen, a force F2 is generated on the squeegee. The rebound force ensures that the screen printing plate, except for the imprint line, does not contact the substrate. Under the squeezing force F1 of the squeegee, the ink passes through the mesh and is printed onto the substrate from the moving imprint line. During the printing process, the screen printing plate and the squeegee move relative to each other, and the squeezing force F1 and the rebound force F2 move synchronously. Under the action of the rebound force, the screen promptly returns to its original position and disengages from the substrate to prevent smudging. In other words, the screen is constantly undergoing deformation and rebound during the printing process.

[0049] After completing unidirectional printing, the squeegee detaches from the substrate along with the screen printing plate and simultaneously returns to the substrate, thus completing one printing cycle. The distance between the top of the substrate and the reverse side of the screen printing plate after the return is called the screen distance, which should generally be 2-5mm. In manual printing, the operator's technique and skill directly affect the formation of the printing lines. In practice, screen printing workers have accumulated much valuable experience, which can be summarized into six points: ensuring the straightness, uniform speed, equal angle, even pressure, centering, and perpendicularity of the squeegee's movement. That is to say, during printing, the squeegee should move in a straight line without swaying left or right; it should not be slow at the beginning and fast at the end, or fast at the beginning and slow at the end, or fluctuate in speed; the tilt angle of the squeegee should remain constant, paying particular attention to overcoming the common problem of gradually increasing tilt angles; the printing pressure should be kept uniform; the distance between the squeegee and the two inner sides of the screen frame should be equal; and the squeegee should be perpendicular to the frame. We adjust parameters such as the contact pressure between the squeegee and the screen, the height between the screen and the substrate, the squeegee stroke, and the squeegee speed to achieve the required printing film thickness and graphic dimensions.

[0050] In the above embodiments, preferably, the film thickness of the first wire mesh is 15-85 μm, and the film thickness of the second wire mesh is 10-75 μm.

[0051] In this embodiment, the film thickness is mainly controlled during the screen making process: a) the electrode screen film thickness is controlled at 15-85μm; b) the resistor screen film thickness is controlled at 10-75μm. The screens of this thickness are made to ensure that the printed film thickness meets the requirements in electrode printing and resistor printing.

[0052] In the above embodiments, preferably, the laser trimming is performed by laser cutting the gate thick film resistor of the IGBT power module using a laser trimming machine, and the cutting shape is I-shaped, L-shaped or U-shaped.

[0053] In this embodiment, in order to complete the laser trimming, a set of trimming probes suitable for this product must first be made. The probes are made according to the test points of this product. Then, the trimming program is compiled according to the graphic size of the product and the required target resistance value. Appropriate parameters are selected for processing; such as: gate thick film resistors with 1, 5, 10, 20, 50, 100Ω, etc. The cut is I, L or U-shaped, and the remaining width must be ≥1 / 5 of the resistor body. After trimming, the resistance value is measured with a resistance tester to see if it is within the required range.

[0054] Laser trimming machine: The principle of laser trimming is to use an extremely fine laser beam to strike a thick-film resistor, cutting the resistor by vaporizing the resistive material. The laser beam cuts the resistor according to a pre-programmed computer program, changing the resistance value by altering the geometry of the thick-film resistor. As the laser cutting process proceeds, a real-time measurement circuit monitors the change in the resistance value of the thick-film resistor. The resistance value continuously approaches the target value. Once the target resistance value is reached, the laser beam is turned off, thus completing the laser trimming process. By setting parameters such as laser power and cutting shape, a preset target resistance value can be achieved. This method offers advantages such as clean cuts, stable resistance values, and high efficiency, ensuring the performance requirements of thick-film resistors are met.

[0055] Gate Thick Film Resistor Performance Testing Serial Number Test content Equipment / Mold Test conditions Qualification Standard 1 Solderability test Solder pot 245±2℃ Tin pot 2S Tinning area ≥ 95% 2 Weldability test Solder pot 265±2℃ Tin pot for 10 seconds △R≤±(1.0%R+0.05Ω) 3 Adhesion test Tensile tester, DBC copper clad laminate Positive electrode vertical tension Vertical tensile force > 150N 4 TCR test TCR test chamber, resistance tester TCR chamber T1=25±3℃, T2=70±2℃, T3=175±2℃, resistivity change rate ≦±200PPM / ℃ 5 Rapid temperature change test High and low temperature test chamber The temperature was set at -40℃±3℃ (30 min) → 25℃±3℃ (5 min) → +175℃±3℃ (30 min) → 25℃±3℃ (5 min) for 1000 consecutive cycles. The recovery time was 1 to 2 hours. △R≤±(3.0%R+0.05Ω) 2. Matching test of gate thick film resistor with IGBT power module: The developed gate thick film resistor was matched with the IGBT power module to verify its performance and stability in practical applications; The testing conditions and passing criteria are as follows: (a) Static parameter qualification standards After connecting the gate thick-film resistor, the gate-emitter threshold voltage of the IGBT module deviates from the threshold voltage without the resistor by no more than ±0.5V, and the threshold voltage is within the range specified in the module's technical specifications.

[0056] (ii) Dynamic performance qualification standards Under rated power supply voltage and load conditions, the turn-on and turn-off times should meet the requirements for drive resistance in the IGBT module technical specifications, and the deviation from the theoretical calculation value should not exceed ±10%. Under different load conditions (20%~100% rated load), the rate of change of switching time should not exceed ±15%.

[0057] The gate voltage waveform should be stable, without obvious oscillations, overshoot (overshoot amplitude not exceeding 15% of the rated gate voltage), and glitches (glitches amplitude not exceeding 5% of the rated gate voltage). The rising and falling edges of the waveform should be smooth, and the rise and fall times should be within the range specified by the module. (III) Load Characteristic Qualification Standards Under different load conditions (20%~100% rated load), the collector-emitter voltage of the IGBT module in the on-state shall not exceed the maximum value specified in the technical specifications, and the voltage change trend with the load current should conform to normal conduction characteristics. The voltage fluctuation across the gate thick film resistor shall not exceed ±5%.

[0058] Under overload conditions (150% of rated load), the module should be able to trigger the overload protection mechanism within a specified time (e.g., 10μs), with accurate and reliable protection action. After the protection is released, the module should be able to start normally without damage or performance degradation.

[0059] (iv) Temperature characteristic qualification standard Under high temperature (+125℃) and low temperature (-40℃) conditions, the resistance change of the gate thick film resistor should be within the static parameter qualification standard range, the threshold voltage change of the IGBT module should not exceed ±1V, the switching time change should not exceed ±20%, and the abnormal phenomena of the gate voltage waveform (such as overshoot and oscillation) should not exceed the dynamic performance qualification standard.

[0060] After temperature cycling testing, the deviations of the device's various performance parameters from those before testing did not exceed the limits specified in their respective qualification standards, and there was no obvious performance degradation or damage.

[0061] (v) Long-term stability qualification standard During continuous operation testing, the resistance change rate of the gate thick-film resistor did not exceed ±0.5% per hour, the threshold voltage change of the IGBT module did not exceed ±0.1V per hour, the switching time change did not exceed ±5% per hour, and the gate voltage waveform remained stable without any gradual deterioration. After the operation was completed, the device appearance showed no obvious changes (such as cracks, discoloration, etc.), and all parameters still met the above-mentioned qualification standards.

[0062] The third embodiment of this utility model provides an IGBT power module, including a gate thick film resistor. The gate thick film resistor is matched with the IGBT gate drive circuit in the IGBT power module. The gate thick film resistor includes a ceramic substrate 1, a positive electrode layer 2 printed on the front side of the ceramic substrate 1, and a back electrode layer 3 printed on the back side of the ceramic substrate 1. A resistive layer 4 is printed on the positive electrode layer 2, a glass layer 5 is printed on the resistive layer 4, and a protective layer 6 is covered on the glass layer 5. The layers are sintered together at a high temperature of 600-1000°C in a sintering furnace.

[0063] Advantages of IGBT gate thick film resistors: High precision Thick-film resistors, produced using processes such as screen printing, allow for precise control of resistance values. Their resistance accuracy reaches a high level, effectively meeting the IGBT gate's requirements for drive resistor precision, thus facilitating accurate control of the IGBT's switching speed.

[0064] High stability The materials and manufacturing processes of thick-film resistors give them excellent stability. Under different operating conditions, such as temperature changes, humidity changes, and mechanical vibration, the resistance of thick-film resistors changes relatively little, which can ensure the performance stability of the IGBT gate drive circuit and thus ensure the reliable operation of the IGBT.

[0065] Good high-frequency characteristics It can adapt to the operating requirements of IGBTs in high-frequency switching conditions. In high-frequency environments, thick-film resistors do not exhibit significant parasitic inductance and capacitance effects like some other types of resistors, thus avoiding adverse effects on the switching performance of IGBTs and enabling IGBTs to perform switching actions quickly and smoothly.

[0066] Strong power handling capacity Thick-film resistors can withstand a certain level of power. During IGBT switching, the gate current causes power loss in the resistor. Thick-film resistors can effectively handle this situation, preventing damage due to power overload and thus ensuring the normal operation of the drive circuit.

[0067] Miniaturization Thick-film technology allows resistors with the required resistance value to be fabricated on a smaller substrate area, which helps to miniaturize IGBT drive circuits and is very advantageous for the design of compact power electronic devices.

[0068] In this utility model, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "join," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "join" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0069] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0070] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A gate thick film resistor for an IGBT power module, characterized by, The device includes a ceramic substrate, a positive electrode layer printed on the front side of the ceramic substrate, and a back electrode layer printed on the back side of the ceramic substrate. A resistive layer is printed on the positive electrode layer, a glass layer is printed on the resistive layer, and a protective layer is covered on the glass layer. The layers are sintered together at a high temperature of 600-1000°C in a sintering furnace.

2. The gate thick film resistor for an IGBT power module according to claim 1, characterized by, The thickness of the resistive layer after sintering is 5-50 μm.

3. The gate thick film resistor for an IGBT power module according to claim 1, characterized by, The ceramic substrate is an alumina ceramic substrate or an aluminum nitride ceramic substrate, with a thickness of 0.2-1.2 mm.

4. The gate thick film resistor for an IGBT power module according to claim 1, characterized by, Both the positive electrode layer and the back electrode layer include a first printing layer and a second printing layer, and the second printing layer is printed after the first printing layer is cured.

5. The gate thick film resistor for an IGBT power module according to claim 4, characterized by, The thickness of the first printed layer after curing is 5-50 μm, and the total thickness of the first printed layer and the second printed layer after curing is 10-50 μm.

6. An IGBT power module, characterized in that, It includes a gate thick-film resistor as described in any one of claims 1 to 5, wherein the gate thick-film resistor is matched with the IGBT gate drive circuit in the IGBT power module.

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